The present invention relates generally to a method and apparatus for measuring the SNR during magnetic resonance imaging, and more particularly, to a method and apparatus for real-time SNR measurement during magnetic resonance imaging.
The use of magnetic resonance imaging has expanded from simple diagnostic imaging into the field of guided surgical imaging. The development of a variety of open magnetic resonance imaging (MRI) systems has facilitated such usages and has resulted in an increase in MR guided surgical interventions. Despite the recent improvements in MR instrumentation, interventional MR imaging often still suffers from low signal-to-noise ratios (SNR) during some interventional procedures. Open MRI systems can be particularly susceptible to such low SNRs.
A good portion of the SNR restrictions are often related to the MR system specifications. These portions can often only be improved by a redesign of the MR system. Often this is not a practical solution. Existing MR systems can represent a significant investment of capital and therefore may not be slated for replacement or reconfiguration for some time. Additionally, design and manufacturing timelines may represent a considerable hurdle for implementation of improvements to the MR instrumentation. Again, while such design improvements are desirable and undoubtedly eventual, an approach to improving SNR that can be implemented on existing systems would be highly valuable.
Although a large portion of the SNR restrictions may be related to the MR system design, the SNR can be significantly influenced by instruments and monitoring devices used during surgery. Anesthesia devices, heart-rate monitors, and a wide variety of other electronic devices can generate noise during operation. The noise emitted by these devices can often be reduced by minor modifications of the surgical setup, such as repositioning devices or cables. Although such repositioning can produce significant improvements to the SNR, the amount of time available for such reconfigurations of the surgical environment is often quite limited before and during surgery. Localized sources of noise must often be quickly identified and repositioned to a desirable position. An immediate, fast, and interactive method of monitoring the effects of changes to the surgical environment would therefore be highly desirable. An effective way of communicating such changes to staff within the surgical environment would also be desirable.
It is, therefore, an object of the present invention to provide an apparatus and method for measuring the SNR during magnetic resonance imaging. It is a further object of the present invention to provide an apparatus and method quickly and simply improving the SNR during magnetic resonance imaging through the use of audio/visual indicators. In accordance with the objects of the present invention, an apparatus for measuring real-time SNR during magnetic resonance imaging is provided. The apparatus includes an image processing engine in communication with a magnetic resonance imaging system. The image processing engine calculates an acquired real-time signal-to-noise ratio based on a real-time image received from the MRI system and compares the acquired real-time SNR to a reference SNR to develop a relative SNR variance. The apparatus further includes an audio output device. The audio output device broadcasts a signal in response to the relative SNR variance. Other objects and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims.